1 files changed, 28 insertions, 0 deletions
diff --git a/docshell/test/unit/AllowJavascriptParent.sys.mjs b/docshell/test/unit/AllowJavascriptParent.sys.mjs
new file mode 100644
index 0000000000..5631fcdb09
--- /dev/null
+++ b/docshell/test/unit/AllowJavascriptParent.sys.mjs
@@ -0,0 +1,28 @@
+let loadPromises = new WeakMap();
+
+export class AllowJavascriptParent extends JSWindowActorParent {
+  async receiveMessage(msg) {
+    switch (msg.name) {
+      case "LoadFired":
+        let bc = this.browsingContext;
+        let deferred = loadPromises.get(bc);
+        if (deferred) {
+          loadPromises.delete(bc);
+          deferred.resolve(this);
+        }
+        break;
+    }
+  }
+
+  static promiseLoad(bc) {
+    let deferred = loadPromises.get(bc);
+    if (!deferred) {
+      deferred = {};
+      deferred.promise = new Promise(resolve => {
+        deferred.resolve = resolve;
+      });
+      loadPromises.set(bc, deferred);
+    }
+    return deferred.promise;
+  }
+}